Composite insulating material



H. F. WEISS.

COMPOSITE INSULATING MATERIAL. APPLICATION FILED JULY 11. 1919.

' 1,336,404. v Patefited Apr. 6, 1920.

' 3/ Cmuins agent OLfiesiva J0 5am @TZual'e'LlaZ Maxim, 4 Cove Ling agent v $7, anoe-m @511 flblfozme/l s ZM/l HOWARD WEISS, OF'MLD-IS ON, WISCONSIN, ASSIGNOR '10 PATENT or-FIo C. I. BURGESS LABORA- .TORIES, 0F MADISON, WISCONSIN, A CORPORATION OF WISCONSIN.

To all whom it ma concern: 7

Be it known t at I, HoWARD F. WEIss, residing at Madison,. in the county of Dane, State of Wisconsin, have invented certain new and useful Improvements in'Composite Insulating Materials; and I do herebydeclare the following to be a full, clear,- and exact description of the invention, such-aswill enable others skilled in the artto which it appertains to make and use the same.

This invention relates to composite insulating materials, and has for its objects the provision of-an improved method of making the same, as well as the provision of a] new article. of manufacture resulting from the practice of the method of the invention.

Fibrous material confined'between sheets of paper, or the like, is extensively used as a heat insulating medium particularly in building construction. It has heretofore I been the general practice to sew the fibrous material between the inclosing sheets of paper. This sewing-of. the fibrous material between these sheets of paper has heretofore beeliiinecessary, because the fibers themselves are not cemented or.fastened to each other in such a manner that they form a felt or fabricated sheet, and unless the inclosing sheets. of paper were sewed, there would be noway in which the sheetsof' paper could be kept in place. The sewing fss - the United States A May 31, 1918, I have described a'method of producing a felt or mat of fibrous mate-' ria is objectionable, first, because itis expensive, second, because it perforates the paper, thereby admitting moisture tothe fibrous material, and third, because the thread freguently breaks off in the process of manuacture,

thus materially reducing the speed and capacity of the manufacturing appa; ratus. v

In my Letters Patent .of Serial No. 237 ,446, filed application for in which the fibersare connected or fastened togetherso as to form a fabric "of .fibers' in heterogeneous arrangement and cemented together with adhesive material:

' I have found that a felt ormat in which 1 body of tion, is admirably adapted a composite 1 insulating material, Thus, I have'dlscovered that such a mat or fined between two inc1osingTsheets .0

Specification of Letters Patent.

comrosrrr. INSULATING MATERIAL.

ric, such as paper, or the like, by coating either the fibrous mat or theinclosing fabric with a suitable adhesive, whereby the fibrous mat is cemented to the inclosing sheets offabric,

In my copending application 'for Letters Patent of the United States, Serial No. 301,218, filed June 2, 1919, I have described in detail and claimed, in its broad aspect, my invention of manufacturing composite insulating material in which a coherent fibrous body portion having the fibers thereof 1 such, for example, as hair. Animal fiber is inherently more or less water resistant, and is on this account welladapted for the production of the coherent fibrous body portion of my insulating material. Animal fibers are, however, difficult to' handle, be:

cause 'of'the tendency of such fibers to felt together in unwieldy balls .or tan led masses. I, For these reasons, it is difiicu t to I Patented Apr. 6, 1920. Application filed m 11, 1919. semi No. 310,136.

sift or screen the animal fibrous material and form of it a heterogeneous-layenof fibers in which the fibers can be cemented or fastened together by an adhesive to produce a coherent fibrousmat or felt. By sub- -je cting animal'fibrous material to a shredding operation, such as described in my aforementioned application No. 237,446, the

fibers may be cut and knocked apart, so that the resulting shredded product can be deposited wit-hout the formation of tan led masses of fibers of uneven thickness. or this purpose, the animal fibers are cut during the shredding operation only to the exhave found thatvery satisfactory results fibers in a hammer mill shredder in which the rotating element makes 3000 or -more v revolutions per minute.

- .the fibers are cemented or fastened together, I

as described in the aforementioned appiicaas the fibrous Thus, in accordance with one phaseof my ne i'sC-arrange'd to discharge the shredded diret y. 11 belt convey in which .tent necessary to secure good felting. I

As pointed out in my aforementioned ap- 'plication, Serial No. 301,218, numerous adhesive agents are available for cementing the fibrous mat between the sheets of inclosing fabric. I have found sodium silicate, asphalt, coal tar pitch, and the like, suitable adhesives for this purpose. Asphalt and pitches, such, for example, as coal tar pitch, are extremely desirable adhesives ,for this purpose, because they render the inclosing fabric moisture and water proof in addition to cementing the same to the fibrous mat.

By suitably selecting the adhesive for cementing the fibers together, the resulting fibrous mat can be rendered fire-proof, ratproof and moistureproof. The adhesive may, for example, consist of' a solution of sodium silicate, or sodium silicate may be in- 1 ing the fi A way in which the desired result may be accorporated with the adhesive as a fire-resistant agent. Ammonium sulfate may also be incorporated in the adhesive as a fire-resistant agent. Water-resistant glue may also beem loyed asthe adhesive for cement- Eers together., A water-resistant glue for the purpose maybe made by adding bichromate of potassium to animal glue and exposing the mixture to strong light. A solution of tar or pitch in a volatile solvent,

such as benzol or the like, can also be used as the adhesive. I have found a solution of coal tar pitch, or asphalt pitch, in carbontetrachlorid, a very suitable adhesive for cementin together animal fibers.

. The brous mat or body portion of the insulating material may be made rat and vermin proof by incorporating therein barium carbonate or beta na-phthol or other suitable chemicals. This result can be satisfactorily accomplished by incorporating the desired chemical in the adhesive for cementing the fibers together, or the desired chemical may be otherwise incorporated in the fibrous mat in any appropriate manner. Similarly, the fire-proofing agent may be incorporated-in thefibrous mat in any appropriate manner, and I have herein mentioned incorporating these chemicals or agents in the adhesive, merely for the purpose of illustrating one complished.

Animal fiber or hair possesses certain characteristic properties which peculiarly adapt it for the body portion of an insulating ma- "terial of the kind herein described. Thus, for example, a light resilient felted mat of animal hair canbe submerged in water and subsequently removed and dried without losing its light and resilient characteristics. On the other hand, a similar mat of wood fibers subjected to'the same treatment would form upon drying a dense mass of fibers resembling blotting paper, and would have none- -of its original characteristics of a light resilient mat with fibers in heterogeneous arrangement. Because of this difference between animal hair or fiber and wood or bark fibers, animal fiber may be successfully treated to secure a light resilient felt or mat in a number of different ways, which are not so well adapted for the treatment of wood or bark fibers. I will, therefore, now briefly refer to certain modifications in the hereinbefore described procedure of producing the light resilient felt or mat of animal hair or fiber contemplated by the present invention.

The animal hair or fiber may be shredded or combed in a shredding engine, onthe like, and deposited upon a suitable support, such as a conveyor or foraminated belt. The fibers will form in a light resilient fabric with the fibers in heterogeneous arrangement, but not cemented together. This uniformly distributed mass of shredded animal fibers is then dipped into or otherwise appropriately treated with a solution contain- .ing adhesive, whereby the fiber-s are cemented together, and, upon drying orsetting of the adhesive, there results a product similar to the fibrous mat hereinbefore described.

The shredded animal fibers may be deposited upon a wire screen, or similar foraminated support, and an adhesive solution or agent poured or flowed upon or over the deposited mass of fibers. Most of this adhesive solution will pass through the fibrous mass and drain oif through the interstices of the support, but a sufiicient amount of the adhesive solution will remain within the fibrous-mass to cement the fibers together and give a product similar to that hereinbefore described.

.A solid adhesive agent may be mixed with animal fibers, and the mixture subjected to treatment in a shredding engine in substantially the same manner as described in my gpplication for Letters Patent of the United tates, Serial No. 292,677 filed April 25, 1919. As the solid adhesive agent or binder coal tar pitch, asphalt, and the like may be used. The shredded fibers and more or less pulverized binder are deposited on an appropriate support, such as a belt conveyor,

the form'of a. loose resilient heterogeneous mass of animal fibers of substantially uniform thickness, throughout which a very large number of extremely fine solid adhesive particles are resent.

' sary that the adhesive a ent or bindermixed deposited from .support in the form of a uniform layer of product will be similar so with the fibrous material and subjected to treatment in a shredding engine be solid or dry, as mentioned in the preceding paragraph. Thus, for example,

dium silicate, in chloroform or other appropriate volatile solvent, may be mixed with the animal fibers in the shredding engine, and the mixture the engine onto a suitable a liquid adhesive agent, such, as an aqueous solutlon of sofibers in heterogeneous arrangement, the fibers being coated with an adhesive in solvent. Upon evaporation or removal of the solvent and drying of the adhesive, the fibers will be cemented together and the resulting to the fibrous mats hereinbefore described. The volatile solventsflmay, of course, be volatilized and re- Y covered and thus used over and over again.

The light resilient mat or felt of animal fibers cemented together in any of the ways hereinbefore. described maybe coated with a layer of asphalt, pitch, rubber, or the like, insteadof being inclosed between sheets of fabric, such as paper, or the like. Thus, for example, the fibrous mat with the fibers cemented together may be passed through suitable coating rolls, appropriately fed from tanks containing the coating liquid, which Will spread a film or coating of asphalt, coal tar pitch, or the like, of the desired thickness onto the exposed surfaces of the fibrous- "mat, thus forming a moisture and'air resist- Y ing covering agent which is directly cement ed to the.fibers of the mat. Such a treatment, of course, eliminates the necessity of described inclosing sheets The shredding operation to which the animal fibers are subjected rior'to their deposition on the support is esigned to separate the fibers into. individual particles, and I have threughout this specification and the appendedf elaims employed the term shredding and its derivatives,in a generic sense, to cribe the operation of so treating the hat each fiberis ny other fiber.

substantially free from Animal fibers are relatively long-and this property is of advantage in the formation ofa monolithic fabric such as the light resilient fibrous mat of my improved 'insulatmgmaterial. Ac-

ing. In practice,

will cement or a solution of pitch or tar form a more or less cordingly, the shredding operationshould be conducted with the view of cutting the fibers as little as possible, and only to the extent necessary to secure satisfactory feltthe shredding of the animal'fibers will usually be most satisfactorily effected in a shredding engine, but the desired result may be secured in other ways, as, for example, b brushing or combing. F or example, a sti wire brush revolving at a high rateof speed and coming in contact with the fibrous material will separate the fibersinto individual particles of the desired character to effect satisfactory felting.

in Figure 1 of the accompanying drawing, there is diagrammatically illustratedin elevation one form of apparatus for carrying outthe invention, but the showing is purely diagrammatic and is given merely tb facilitate a complete understanding of the invention. F or this reason, the precise structural details of the apparatus are omitted, as

forming no part whatever of the present lnvention. I

Figs. 2, 3, 4 and 5 of the drawing illustrate various modifications in the form of the composite insulating material produced in accordance with the invention.

Referring to Fig. lof the drawing, there is shown a shredding engine 10 for cutting the animal fibers and knocking them apart. The purpose of this shredding operation is to separate the fibers into individual particles of such a character thatthey can be deposited on a support to form a more or less 'flocculent layer of heterogeneously'arranged .fibers adapted to .be cemented or fastened together by an adhesive agent to form a coherent fibrous mat. During this shredding operation, the fibers are only cut to I the extent necessaryto facilitate their depos'ition' in a layer of the character contemplated. I have found that hair may be satisfactorily shredded for the purposes of the present invention, without balling or tangling up, in a hammer mill'shredder rotating at 3000 or more R.'P. M.' The animal fiber, such as hair, is fed into the shredding engine 10 from an endless belt or conveyor 6 provided with .transversely arranged baflies or paddles 7 for the purposeof keeping the fiber on'the belt of approximately uniform thickness. The belt 6 carries the fiber to the mouth of the shredding engine where it is fed, by a conveyor 8, into the shredder 10 between rolls 9.

. The shredding engine 10. is arranged to discharge the shredded animal fibers on to a belt conveyor 12, preferably of the form of a screen conveyor. The animal fibers are thus cut,- to the necessary extent, and knocked apart in the engine 10, and, falling through the discharge thereof, the so-treated fibers are deposited on the conveyor 12 to fiocculent layer of the desired thickness. I find it desirable to subject the fibers to a slight suction during and directly after their deposition on the conveyor 10. To this end, a suction chamber 13 is arranged below the shredder 10, and directly beneath the supporting screen surface of the conveyor 12. The conveyor 12 may be in the form of a screen'of suitable mesh or its supporting surface may be composed of a suitably perforated or foraminated material, so that the fibers deposited on the conveyor may be subjected to the action of the suction appliedben'eath the conveyor.

Sprayers 14 are suitably arranged for spraying'the fibers with an adhesive agent as theyare deposited on the conveyor 12. The sprayers 14 serve to discharge the adhesive, either directly upon the fibers deposited upon the conveyor or outwardly in the form of a spray or mist through which the fibers fall. These sprayers may be placed directly under the discharge of.

the shredder 10, or to one side thereof, either arrangement proving satisfactory. In either case, the adhesive serves to bind or cement the fibers together, but I have found 4 been found desirable to deposit a very thin that when these fibers fall through a mist or spray of the adhesive, a somewhat firmer mat 'or felt containing fewer loose fibers is produced. In some instances, it has also layer of dried fibers upon the conveyor be fore the application of the adhesive solution, to provide a cushion, which will act to prevent the fibers from sticking to the conveyor.

The layerof shredded fibers deposited on I the conveyor 12 is borne along by the conveyer to a drying chamber 15. A suitable drying medium may be passed through the chamber 15 for the purpose of drying the layer of fibers carried along by the conveyor 12. The chamber 15 is thus represented in the drawing as having an entrance conduit 16 and an exit conduit 17 for passing a drying or heating medium such as heated air, through the chamber 15. Where the adhesive for cementing the fibers together contains a volatile solvent, it will'be observed that' the solvent may be removed while the fibrous mat is passing through the drying chamber 15 and may be recovered by suitably treating the vapor pass ing from the chamber 15 through the exit conduit 17. When using an adhesive which dries or sets quickly,'the drier 15 can, if desired, be entirely omitted, although its use is preferred. Thus, for example, with such adhesives as sodium silicate, I find that drying in a room is sufficient, but that a drier speeds up the rate of drying and for this reason is desirable.

The mat or felt of fibrous 1 material, formed in the manner just described, 15 next confined or inclosed between sheets of fabric in order to produce the insulating material of the invention. The fibrous mat or felt, after passing through the heating chamber 15, is accordingly passed between two rolls 18 over which are passed sheets hesive material w en they pass over the rolls 18 and the pressure produced by the rolls 18 is sufficient to securethe fastening or cementing of the inclosing sheets of fabric to the fibrous body mat. Thus, the

completed insulating material passes from .the rolls 18 onto a conveyor 22, whereafter it is wound into a roll or disposed of in any desired manner.

The finished product produced inthe manner hereinbefore described comprises a body portion of animal fibers, in which the fibers are cemented or fastened together, confined or inclosed between sheets of fabric, which are also cemented to the fibrous body-portion. In Figs. 2, 3, 4 and 5 of the drawing, the fibrous body portion of the insulating material is represented by reference character 30, and the sheets of the inclosing fabv ric are represented by reference characters 31 and 32. Where it is desired to inclose the side edges of the insulating material, .the fabric sheets 31 and 32 may be folded over to form a seal at the sides of the insulating material. Thus,in Fig. 3, the upper fabric sheet 31 is foided over one edge of the insulating felt and secured to the lower fabric sheet 32 in any suitable manner, while the lower fabric sheet 32 is similarly folded over the other edge of the insulating felt and secured to the fabric sheet 31. As shown in Fig. 4, the edges of the insulating felt may be sealed or inclosedby a strip of fabric 33 folded over the edge and secured to both the top and bottom inclosing sheets in any suitable manner. In Fig. 5, I have shown the edges of the insulating felt sealed or closed by compressing a relatively narrow strip a ong each edge thereof- This operation may be conveniently performed before the adhesive coating on the sheets 31 and 32 has dried or set.

7 As the fibers drop from the discharge of the shredder 10 on to the screen conveyor 12, they arrange themselves in a loose heterogeneous mass, with the fibers'extending in all three cubical dimensions. 'The suction applied through the chamber 13 is so regulated as not to form the fibers in too firm a mass. The adhesive agent sprayed on these fibers by thesprayers 14 serves to fasten the fibers -or the like, as hereinbefore described,'promum of pressure on them and fibers are not easily dislodged. As a result of these characteristics of the fibrous body portion of my improved insulating material, I am able to cement thereto covering agents, such as sheets of fabric, or moisture and air resisting coatings, thus entirely eliminating the necessity of sewing covering sheets to the fibrous material or to each other.

. Greatest cubical lightness and resiliency are secured by drying the fibers with a minipreferably with no pressure at all. Thus, in practising the invention, pressure on the fibers after.

they have been formed into the heterogeneous resilient fabric is kept at a minimum until after the adhesive has set or hardened and the fibers thereby cemented together. As previously pointed out, one of the characteristic features of the fibrous mat or felt of my improved insulating material resides in the fact that the fibers extend in all three cubical dimensions, whereby a single layer or monolithic fabric of cemented-together fibers is obtained. Such a monolithic fabric in which the fibers are cemented together in heterogeneous arrangement to form a light admirably and resilient fibrous mat or felt is adapted as the body portion of an insulating material and when inclosed between appropriate covering agents, such as sheets of abric or coatings of asphalt, pitch, rubber duces an improved insulating material superior to any .prior product of this general character with which I am acquainted.

claim:

I. The method of manufacturing composite insulating material, which comprises "d'e positing animal fibers upon a support to form a layer of the desired thickness, treatmg the fibers with an adhesive to cement them together, and cementing a covering agent to one or more surfaces of the fibrous mat so produced; substantially as'described.

2. The method of manufacturing composite insulating material, which comprises subjecting hair to a shredding operation for cutting and knocking apartthe. fibers, depositing the so-treated hair upon a support to form a layer of the desired thickness and treating the same with an adhesive to cement the fiberstogether,.andcementing a covering agent to one or more surfaces of the fibrous I mat so produced; substantially as described.

ingthe so-treated hair. into a monolithic fa me 'by cementingth'e fibers thereof to gether with a. water resistant adhesive, and

cementing a covering sheet to one or more surfaces of said fabric by means of a water resistant adhesive; substantially as described.

4. The method of manufacturing composite insulating material, which comprises forming a monolithic fabric of animal fibers cemented together in heterogeneous arrangement, and cementing a covering agent to one or more surfaces of said fabric, substantially as described.

5.' As a new article of manufacture, a composite insulating material comprising a fabric of animal fibers cemented together by an adhesive and having one or more surfaces thereof secured to a covering agent; substantially as described.

6. As a new article of manufacture, a composite insulating material comprising a fabric of animal fibers cemented together by a water resistant adhesive and having one or more surfaces thereof secured to a covering sheet by means of a water resistant adhesive; substantially as described.

7 As a new article of manufacture, a composite insulating material comprising a body portion of. cemented together animal fiber having its front and back surfaces covered by an adhesive, and covering sheets secured to the front and backsurfaces of said body portion by said adhesive; substantially as described. i

8. As a new article of manufacture, a composite insulating material comprising a body portion of hair having at least one surface thereof covered by a water resistant adhesive, and a covering sheet secured to said body portion by said adhesive; subbody portion composed. of hair particles cemented together with a water resistantadw hesive, and a covering sheet secured to one or more-surfaces of said body. portion by means of a water resistant adhesive; substantially as described.

11. As a new article of manufacture, a composite insulating material comprising a monolithic fabric of animal fibers cemented together in heterogeneous arrangement and havlng a covering agent cemented to one or more surfaces thereof; substantially as described. v

12. As 'anewarticle of manufacture, a composite insulating material comprising a resilient mat of cemented-togetheranimal fibers having a covering'agent cemented to sheet secured to'one or more surcomposite insulating ignaterial comprising a one or more surfaces thereof; substantially as described. I V

13. The method of manufacturing composite insulating material, which comprises 5 subjecting hair to a shredding operation for cutting and knocking apart the fibers, depositing the so-treated hair upon a support to form a layer ofthe desired thickness and spraying the same with an adhesive while the hairs are being deposited and immedi- 10 ately after they are deposited on a support to cement the fibers together,,and cementing a covering agent to one or more surfaces of" the fibrous mat so produced; substantially as described. '15

In testimony whereof I aflix my signature.

HOWARD F. WEISS. 

